Tumbler lock plug



March 4, 1952 K N 2,587,739

TUMBLER LOCK PLUG Filed Aug. 13, 1946 WWW/6 Patented Mar. 4, 1952 UNITED: STATES assgase TUMBLER. LOCK.- PLUG V PaulAlb'ert K-i nz Geneva, switaerland, assig'n'or to. Mefina 8.. Ag, Binninge'n'; a" corporation of Switzerland".

ApplicationzAugu'sti 13, 1946,. erial No. 690,2 61' In Switzerland September 3-, 1945 I 2*Claims. (c1. ro ster vIn cylinders for security locks provided with blades placed in position by a key for allowing rotation or the locking of the'cylinder, the blades are generally guided by elements stacked. one upon the. other and held: rigidly in positionby clamping members.

The stack of elements forms the cylinder and it will be evident that their machining on the one hand and their assembly on the other hand, is extremely expensive and requires a relatively long period of time.

The present invention has for its subject a method of production of a cylinder for a security lock provided with members movable perpendicularly to the axis of the cylinder. This method tends to reduce the disadvantages referred to by the fact that grooves are machined in a body having a central opening of approximately rectangular cross-section, these grooves being provided of such depth that they communicate directly with the internal opening of the body through the two smaller sides of its rectangular cross-section so as to allow the passage of movable members of the lock, and that the lateral walls of the opening, and of the grooves, form guides for these members.

The present invention also has for its subject a cylinder obtained by this method and which is distinguished from known cylinders by the fact that it is formed by a portion of a body having an internal opening of approximately rectangular cross-section and a number of grooves equal to the number of movable members with which the lock is provided, these grooves communicating directly with the internal opening of the body through the two smaller sides of the rectangular section of the latter, so that the lateral walls of the opening and of the grooves form guides for the said movable members.

A cylinder obtained by the method is shown diagrammatically and by way of example in the accompanying drawing in which:

Fig. 1 is a perspective view of a lock cylinder with parts broken away; and

Fig. 2 is a perspective view of a lock cylinder with tumbler mounted therein.

The cylinder is formed by a body portion I provided with an internal opening 2 co-axial with the longitudinal axis of the body and having a cross-section approximately in the form of a rectangle. Grooves 3 are machined in the outer wall of the body in a number equal to the number of movable members with which the lock is to be provided. The depth of these members is such that they communicate directly with the internal. opening of the body through the two small sides of the rectangular section of this opening? and in such a mannerthat' the open ingsfll" thu'sfo'rmed have the same length a as 5 thesaidTectangularsection of the internal open- From the foregoing and by examination of the accompanying drawing, it will be seen that it is directly possible to mount the movable members of the lock in the cylinder, each of these members passing from opposite sides of the cylinder through the openings 4 and are guided on the one hand by the lateral Walls of the internal opening and on the other hand by the Walls of the grooves 3 which have been formed.

In the form of construction shown in the accompanying drawing, the two small sides of the internal opening 2 are formed by a sector of a cylinder co-axial with the body, in such a mango ner as to allow machining of the grooves 3 by shaping without risk of deterioration of the tool at the moment at which it enters the internal opening of the body.

It will be clear that the method of manufacture described above permits exact and very rapid for securing together the stacked parts are necessary. Further, the rigidity of the cylinder is entirely satisfactory and its precision much greater.

This thus results in considerable economy in time, whilst avoiding the variations in length of the cylinder due to differences in the thickness of the stacked elements.

I claim: a: 1. A cylinder for a security lock provided with a series of tumblers movable perpendicularly to the axis of the cylinder, in'which the said cylinder is formed by a body portion having an internal axially extending key opening oblong in cross-section and having narrow and wide walls,

46 a plurality of axially spaced and circumferential grooves equal to the number of tumblers with which the lock is provided, said circumferential grooves being of a width equal to the thickness of the tumblers and of a depth greater than 50 the difference between the external diameter of the cylinder and the transverse dimension of the wide walls of the key opening, but of a depth less than the difference between the external diameter of the cylinder and the transverse dimension of the narrow walls of the key opening so that the circumferential grooves communicate ing of oblong cross section having two narrow walls and two wide walls extending axially through the plug and symmetrically disposed relative to the axis of theplug, and forming a plurality of axially spaced tumbler chambers in said cylinder by machining a plurality of axially spaced, circumferentially extending grooves of rectangular cross section in the external surface of the cylinder of a width equal to the thickness of the tumbler chambers and of a depth greater than the thickness of the material of the cylinder between the narrow walls of the. keyway and the external surface of the cylinder, but of a depth less than the thickness of the material of the cylinder lying between the wide walls of the keyway and the external surface of the cylinder to provide diametrically disposed axially spaced tumbler guiding openings at the intersections of the bottoms of the grooves and the narrow walls of the keyway opening.

PAUL ALBERT KUNZ.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 183,035, Young Oct. 10, 1876 487,194 Mossberg Nov. 29, 1892 1,099,494 j. Eletcher June 9, 1914 1,736,685 Wilder Nov. 19, 1929 1 1,867,137 Carver July 12, 1932 1,953,535 J Hum Apr. 3, 1934 1,979,939 Jacobi Nov. 6, 1934 2,060,626 Lach Nov. 10, 1936 2,232,137 Rolph Feb. 18, 1941 2,342,340 Hickling Feb. 22, 1944 FOREIGN PATENTS Number Country Date 660,796 Germany June 2, 1938 

